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Theses

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20002
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Subject: Fisheries × End date: 2000 × Start date: 2000 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Studies on the electrophoretic pattern of Fish/ Shellfish proteins subjected to frozen storage
    (Department of Processing Technology,College of Fisheries, Panangad, 2000) Bomy, Chummar; KAU; Nambudiri, D D
    Freezing considered as an excellent process for preserving the quality of fish for longer periods. But freezing may affect various flesh components, especially the proteins. Sarcoplasmic proteins play a major role in species identification of fish and fishery products. While myofibrillar proteins play a major role in the jellying properties of surimi and surimi based products. The changes to these groups of proteins due to freezing and frozen storage have received much attention. Four species Megalaspis cordyla, Labeo rohita, Penaeus indicus and Parapenaeopsis styli/era were used for the frozen storage study. Samples were stored for 90 days at -18°C and samples were collected at 15 day. intervals and Salt Soluble Nitrogen (SSN), Water Soluble Nitrogen (WSN) and Non-Protein Nitrogen (NPN) content were determined. Electrophoretic pattern of both Salt Soluble Proteins (SSP) and Water Soluble Proteins (WSP) of frozen stored sample were compared with that of the fresh sample.
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    ThesisItemOpen Access
    Lethal and sublethal toxicity of monocrotophos an organophosphate on the juveniles of rohu labeo rohita (ham.) under tropical conditions
    (Department of Fishery Biology, College of Fisheries,Panangad, 2000) Ramani, M B; KAU; Anna Mercy, T V
    The seasonal utilization of paddy field for fish culture is quite common in Kerala and West Bengal. In recent years, with the advent of high yielding varieties of paddy, the use of pesticide has become widely prevalent. Monocrotophos is one of the commonly used organophosphate pesticides in the paddy fields of Kerala. The present study was designed to arrive at an experimentally determined application factor for fixing tentative water quality criteria for monocrotophos under tropical conditions. Juvenile Rohu Labeo rohita (46.82 ± 0.S2 mm total length, 1012.29 ± 43.12 mg wet weight) were subjected to static lethal and sublethal bioassay. The 48 h LCso value was found to .be 104.02 mg/I at 28 ± 2°C. Juvenile Rohu were exposed to sublethal monocrotophos concentrations (2, S, 1 a, 1S, 20 and 30 mg/l) for 32 days at 28 ± 2°C without aeration. Treatment media were replaced every 24 hr. Fish were fed a pelleted diet at 6% wet body weight per day. Rohu exposed to S, 1 a, 1S, 20 and 30 mg/l monocrotophos showed significantly lower mean wet weight gain, specific growth rate (SGR) and food conversion efficiency (FCE). But fishes of lower monocrotophos concentration of 2.0 mg/I were not significantly different from the control. Juveniles exposed to 2, S, 1 a, 1S, 20 and 30 mg/I monocrotophos concentrations had higher moisture and ash content, and lower protein, lipid and carbohydrate contents, as body nutrients were depleted. The maximum acceptable toxicant concentration for juvenile Rohu was 3.16 mg/l for S~R and FeE as end points (the most sensitive) and 24.S mg/l for percentage survival as an end point (the least sensitive) indicating application factors of 0.03 and 0.24 respectively.